First Record of Dark‐sided Flycatcher ( <i>Muscicapa sibirica</i> ) for Temperate North America: Intercontinental Vagrancy and Migratory Misorientation

. We identify it as a member of the nominate subspecies, therefore likely originating from highly migratory populations that breed in northeast Asia. We evaluate mechanisms by which this individual may have arrived in California and discuss the concepts of reversal and mirror-image misorientation, modes of anomalous navigation that may provide explanations for Palearctic-Nearctic vagrancy in highly migratory Asian passerines. Our observation represents a noteworthy addition to the known avifauna of temperate North America. In documenting this occurrence, we draw attention to the remarkable but little-studied process of long-distance vagrancy in migratory birds.